1. Field of the Invention
The present invention relates to an alarm management system for acquiring message data for alarms issued from a process and analyzing alarm behaviors.
2. Description of the Prior Art
Prior art documents related to an event analysis system that acquires and analyzes message data for alarm events, for example, produced from a process include the following.                [Non-patent document 1]        URL: http://www.yokogawa.co.jp/EXASOFT/13_Exalog/exalog—01.htm        Exaplog event analysis package        
FIG. 1 is a function block diagram illustrating the configuration of an alarm management system disclosed in the GS36J06A10-01 general specifications document downloadable from the web page where non-patent document 1 is placed. The server acquires produced alarm messages (with process data at the moment each message was produced) from the historical message file, which is a log of plant operations kept by the distributed process control system (DCS), and stores them.
The processing functions of the alarm management system include:    (1) outputting the saved data to the display or printing or referencing the data;    (2) examining the cause of alarm issuance and the necessity of such alarms using an analysis tool (quantification using trend graphs or classification using pie charts and tables);    (3) correcting the cause of unnecessary alarms being issued in order to prevent the alarms from being inadvertently reissued; and    (4) modifying the alarm functions, rather than using function (3) above, in order to temporarily prevent the unnecessary alarms from being issued.
Alarms issued from a process include those attributable to alarm setpoints, tag ranges or control parameters that were incorrectly defined in an engineering phase. There is therefore the need for suppressing such alarms among those included in the appropriate population of alarms under alarm data analysis.
When reviewing unnecessary alarms using a conventional alarm management system, the assigned engineer must identify such unnecessary alarms from among as many as several thousand or several ten thousand alarms. Then the engineer must identify the causes (for example, incorrect tag ranges) of these alarms and correct them one by one, incurring enormous amounts of engineering man-hours. This work has been extremely troublesome for engineers who face labor-saving staff cutbacks.
In order to identify unnecessary alarms, engineers having appropriate professional skills and experience are needed. Often, however, it is impossible to secure the appropriate personnel, making it difficult to precisely select unnecessary alarms.